Jennie Garth is proud of her slimmer shape!

During her cover shoot for the January/February cover of Health, the 40-year-old actress explained how she lost 30 pounds midway through 2012 -- and also revealed how she's been able to keep the weight off.

"I've been working out really hard. I've been weight training with a trainer three days a week. We do boxing, kickboxing -- lots of weight lifting and training and jumping all around like crazy people," the mother of three laughed. "I really never sit down! I think that's basically the secret -- not sitting around."

Though fitness is a priority for the Beverly Hills, 90210 star, maintaining a balanced diet is equally important. "One of my favorite healthy things to eat is salad with beets on it. I love beets. I can't get enough beets lately," the 5-foot-5 actress said. "I like to eat them or drink them."

To see more behind the scenes moments from Garth's Health photo shoot, watch the video above now!

This article originally appeared on Usmagazine.com: Jennie Garth Shares Her Diet and Fitness Tips for 2013